1. Field of the Invention
The present invention relates to a mounting structure for a canister vent valve. More specifically, the present invention relates to a mounting structure for rotationally fixing a canister vent valve to a canister in different angular positions relative to each other.
2. Background Information
A conventional method of mounting various types of control valves to a canister that adsorbs fuel vapors produced inside a fuel tank is described in Japanese Laid-Open Patent Publication No. 8-210530. In this publication, a pair of notches is formed in 180 degrees opposing positions in a rim of an insertion hole formed in the canister and a pair of complementary projections is formed on an outside circumference of a pressure pipe provided on the control valve. Both of the notches are shaped such that the projections can be inserted therein. In order to mount the control valve on the canister, the pressure pipe is first inserted into the insertion hole. Then, the control valve is rotated 90 degrees about the center axis of the pressure pipe such that the projections pass through the notches. Then, after the pressure pipe has been inserted into the insertion hole and the tip of the pressure pipe has touched against an inner flange formed on an inside circumferential wall of the insertion hole, the mounting is completed by rotating the control valve in the opposite direction with respect to the canister while the projections fit into respective groove parts formed in the inside circumferential wall of the insertion hole. This structure also includes an O-ring that seals the space between the outside circumference of the pressure pipe and the inside circumference of the insertion hole. The control valves mentioned above are solenoid valves and diaphragm valves. These valves usually have specified limits regarding their mounting angles with respect to the vehicle body in order to ensure the performance of the valves.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved canister vent valve mounting structure. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.